Sheet control apparatus



March 11,1969 DALE ETAL 3,432,161

SHEET CONTROL APPARATUS Filed Oct. 13, 1966 Sheet of :5

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ATTORNEYS March 11, 1969 DALE ET AL SHEET CONTROL APPARATUS Sheet Filed Oct. 13, 1966 INVENTFOR.

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INGVALD v DALE CHARLES ,B. LEWIS INVENTORS ATTORNEYS United States Patent 3,432,161 SHEET CONTROL APPARATUS Ingvald Dale, Hoquiam, and Charles B. Lewis, Aberdeen, Wash., assignors to Lamb-Grays Harbor Co., Inc., Hoquiam, Wash., a corporation of Washington Filed Oct. 13, 1966, Ser. No. 586,404 US. Cl. 271-46 13 Claims Int. Cl. B65h 29/68, 29/58 ABSTRACT OF THE DISCLOSURE A sheet control apparatus employing suction to control sheet speed, or direction, or both comprises an outer moving surface exposed to the sheet material with openings therethrough and an inner rotary valving mechanism having at least one opening periodically communicable with the openings through the outer moving surface such that vacuum means may draw a continual negative pressure in the rotary valving mechanism with suction applied periodically to the outer moving surface openings whenever the opening in the rotary valving mechanism is in registry therewith.

This invention relates to apparatus for handling sheet material. More particularly to apparatus suitable for high speed handling of sheet material being fed from a sheet cutting station to a sheet stacking station by applying suction to selected sections of the sheets as they pass a control station.

It is known in the art to apply suction to sheet material as it passes over a control station employing a rotating perforated roll through which air is withdrawn. However, such devices either apply suction continuously or control the suction by some external means, such as complicated sheet sensing and air cut off valve system.

Other devices employ a stationary sheet contactingsuction arrangement whereby the sheet material is stalled unless a secondary system is applied to counteract the elfects of the suction. This is undesirable since the secondary system perameters of operation will change with sheet speed and density, and the type of conveyor system employed, thereby necessitating the use of sheet trans port means downstream of the suction device.

A primary object of this invention is to provide a sheet control apparatus employing suction to control sheet speed, or direction, or both that does not sutfer from the deficiencies inherent in prior devices. Another object is to provide such apparatus that automatically applies suction for a predetermined period without complicated valving mechanisms. A further object is to provide such apparatus that can be adapted to apply suction to sheet leading edges, trailing edges, or any section inbetween as suits the particular application of the apparatus.

These and other objects and advantages of this invention will become apparent from the following disclosure and the accompanying drawings, of which:

FIG. 1 is a top plan view of one embodiment of the sheet control apparatus of this invention;

FIG. 2 is a forward side elevation view of the FIG. 1 embodiment;

FIG. 3 is a cross section taken along the line 3-3 of FIG. 2;

FIG. 4 is a schematic illustrating the application of the invention to retard sheet material from a high speed 'ice conveyor to a low speed conveyor such that the sheet material is overlapped on the low speed conveyor;

FIG. 5 is a schematic illustrating the application of the invention to discharge sheet material from a conveyor directly into a layboy stacking station;

FIG. 6 is a schematic illustrating the application of the invention to direct sheet material downward to a secondary conveyor;

FIG. 7 is a cross-section of another embodiment of the sheet control apparatus of this invention; and

In brief, the sheet control apparatus of this invention comprises means providing an outer moving surface exposed to the sheet material with openings therethrough, an inner rotary valving mechanism having at least one opening periodically communicable with the openings through the outer moving surface, and vacuum means drawing a continual negative pressure in said rotary valving mechanism such that suction will be applied through the outer moving surface openings whenever the opening in the rotary valving mechanism is in registry therewith. The rotational speed of the rotary valving mechanism is timed to effect a suction to draw a predetermined sheet material section onto the outer moving surface for control of the sheet speed, direction or both. For example, when the apparatus is employed as a sheet retarde'r to slow down high speed sheets, the rotation of the rotary valving mechanism could be timed such that the openings in the rotary valving mechanism and the outer moving surface will be aligned as the trailing edge of each sheet to be retarded passes across the outer moving surface Such that each sheet trailing edge will be drawn onto the lower speed outer moving surface for continued travel at such lower speed. As another example, when the apparatus is employed as a sheet deflector the rotation of the rotary valving mechanism could be timed such that the openings in the rotary valving mechanism and the outer moving surface will be aligned as the leading edge of each sheet to 'be deflected passes across the outer 'moving surface such that the sheet leading edge will be drawn onto the outer moving surface for deflected travel in a difierent direction at the speed of such outer moving surface.

One embodiment of the sheet control apparatus of this invention comprises concentric inner and outer cylinders rotatable independently of one another. The outer cylinder is provided with a plurality of perforations. The wall of the inner cylinder is provided with at least one longi tudinal slot so located that air can be drawn through the outer cylinder perforations into the inner cylinder interior through the slot to effect periodic suction that draws sheet material onto the outer cylinder for control of the sheet speed, direction, or both. The inner cylinder is timed for rotation at a speed suflicient to effect a predetermined number of revolutions, per sheet of sheet material passing across the apparatus. The outer cylinder is designed for rotation at the speed at which the sheet material is to leave the control apparatus. The inner cylinder rotation is synchronized such that suction will be applied to the leading edge, trailing edge, or an intermediate section or sections of the sheet .material passing in the sheet conveyor surface to the inner cylinder. The wall of the inner cylinder is provided with a longitudinal slot so located that air can be drawn through the spaces between the tapes into the inner cylinder interior through the slot to effect periodic suction that draws sheet material onto the tapes for control of the sheet speed, direction, or both. The inner cylinder is timed for rotation at a speed sufl'lcient to elfect a predetermined number of revolutions per sheet of sheet material passing across the apparatus. The conveyor tapes travel at the speed at which the sheet material is to leave the apparatus. The inner cylinder rotation is synchronized such that suction will be applied to the leading edge, trailing edge, or an intermediate section or section of the sheet material passing across the apparatus.

Referring to FIGS. l3, one embodiment of the sheet control apparatus of this invention comprises a rotatable highly-perforated outer cylindrical roll 10, a slotted inner cylindrical roll 12 concentrically extending through outer roll and rotatable independently of roll 10, and a vacuum chamber 14 enclosing the rolls 10 and 12. Inner roll 12 is connected to axial left and right hand end shafts 16 and 18 which are rotatably journaled in left and right hand bearing blocks 20 and 22. Bearing blocks 20 and 22 are attached to left and right hand mounting plates 24 and 26. Outer roll 10 is rotatably carried by left and right hand cylindrical bushing members 28 that ride on left and right hand annular bearings 30 connected to end shafts 16 and 18-.

The vacuum chamber 14 comprises left and right hand end walls 32 which peripherally enclose the side and bottom portions of the outer roll 10, and rearward and forward side walls 34 and 36 which extend between the end plates 32 and define a longitudinal opening 37 leading from a vacuum plenum 39 to the lower rearward side I of the concentric rolls 10 and 12. Longitudinal sealing strips 38, 40 and 42, having arcuate inner faces, are connected to the side walls as shown to sealingly contact the outer roll upper rearward side above opening 37, bottom side forward of opening 37, and forward side between seal strips 38 and 40, respectively.

Inner roll 12 is provided with two longitudinal slots 44 and 46 extending through the roll wall and positioned in adjacent quadrants such that when slot 44 is adjacent to vacuum chamber opening 37, slot 46 will be between seal strips 42 and 38. Inner roll 12 is also provided with a plurality of longitudinal sealing strips 48 imbedded in the roll wall and extended outward in sealing contact with the inner surface of outer roll 10.

The vacuum plenum 39 is provided with a valve 54 that is operated by a worm gear assembly 56. Valve 54 controls the amount of air drawn from the vacuum chamber 14 out through vacuum plenum 39 by suitable means such as a high capacity eduction fan. With the valve 54 set to permit a desired outflow of high volume, low pressure air, whenever slots 44 and 46 are properly positioned, air will be drawn through the system thereby creating a suction that will draw a paper sheet passing over the apparatus down onto the outer roll 10.

Outer roll 10 is adapted to be driven by a belt system through pulley 50 which forms the outer end of left hand bushing member 28. Inner roll 12 is adapted to be driven by a belt system through pulley 52 connected to the end of left hand end shaft 16. Inner roll 12 is driven at a speed sufficient to match the speed of the cutter fiybar such that there will be one rotation for each sheet cut by the cutter flybar, regardless of sheet length. Thus, the slots 44 and 46 will be properly positioned to apply suction to an over-passing sheet each time a sheet is conveyed across the apparatus. Outer roll 10 is driven at a speed sulficient to retard or maintain the sheet material at a desired speed as it leaves the apparatus. Thus, application of suction to a sheet will draw it onto the periphery of the rotating outer roll 10 and change its speed to that of the outer roll 10. As outer roll 10 rotates during the suction cycle, the sheet will be carried by outer roll 10 as though it were glued thereto. When slot 44 is rotated opposite the seal strip 38, the suction cycle will terminate and the sheet will cease contact with the outer roll 10.

The angle between slots 44 and 46 and the length of the arcuate face of seal strip 38 can be varied to control the time period during which suction is applied to a sheet. For example, an angle less than will effect a very short suction period and an angle greater than 90 will effect a longer suction period.

A guide plate 43 is connected to the upper forward section of the vacuum chamber 14 to guide the passage of sheet material across the concentric rolls.

Referring to FIG. 7, another embodiment of the sheet control apparatus of this invention comprises a moving belt section travelling at a reduced speed with a full length rotary valving mechanism mounted under the belt section. The rotary valve is so constructed as to allow periodic alignment of ports in the rotary valve and ports in a concentric housing. This results in pulses of vacuum to the underside of the reduced speed belt section and draws a predetermined section of the sheet material onto the moving belt surface. The apparatus comprises a slotted rotatable inner cylindrical roll 112 mounted in a suction chamber 114, and an outer tape conveyor enclosing chamber 114 and comprised of a plurality of endless tapes uniformly spaced apart that travel on pulleys 110a, 1101) and 110C. The upper end of chamber 114 is open to the upper horizontal course of the tape conveyor and is partitioned into longitudinal passages by elongated seal strips that sealably contact the periphery of roll 112. As a slot 113 in roll 112 sweeps past the longitudinal passages in the upper end of chamber 114, air is drawn into the roll 112 from between the conveyor tapes and is exhausted from the roll 112 by suitable evacuating means communicating with an end of roll 112. Because the slot 113 only draws air through the conveyor tapes periodically, the evacuating means can be operated continuously with a resulting pulsating suction effect at the upper end of chamber 114. When the slot 113 is rotating outside of the outermost seal strips 115, no suction effect is created at the upper end of chamber 114.

The apparatus of FIG. 7 is shown as a sheet retarder for depositing sheet material from a high speed conveyor 2 directly into a stacker or layboy 4 at a reduced speed. This apparatus is equally applicable to retarding and delivering sheet material to a low speed conveyor or for deflecting sheet material to a different conveyor course.

Taking FIGS. 3 and 4 as an example, the sheet control apparatus 1 could be positioned between a high speed sheet conveyor 2 leading from a sheet cutting assembly and a low speed sheet conveyor 3 leading to a layboy box 4. In this configuration, the sheet control apparatus 1 is employed as a sheet overlapping mechanism wherein the sheet speed of one sheet is retarded to permit a following sheet to overlap the retarded sheet preparatory to sheet discharge from the low speed conveyor into a layboy box. In this embodiment, the inner control roll 12 is rotated at the speed of the cutter flybar, for example by a mechanical drive from a cutter flybar, the outer roll is rotated at the speed of the low speed conveyor 3, and the apparatus is synchronized to apply suction to the trailing edge of each over-passing sheet.

The advantages of this method of sheet deceleration over existing methods of decelerating a sheet by its leading edge are: (1) no damage to the leading edge of the sheet, (2) no possibility of sheet buckling (and accompanying interruption of sheet flow), and the inherently higher deceleration values possible. The vacuum sheet control mechanism makes use of high-volume, low-pressure vacuum, evacuating a large quantity of air from below the sheet in a small amount of time, permitting high cycle rates. The use of vacuum also eliminates the possibility of damage to a sheet which may accompany the use of mechanical devices to retard a sheets velocity by its trailing edge. A sheet flows from the high speed tapes onto the low speed tapes at high speed until the trailing edge of the sheet is over the unit. At this time, the slots in the control roll will have rotated to the Vacuum On position and the trailing edge of the sheet will be pulled down onto the perforated roll, causing the sheets speed to be reduced to that of the preforated roll. Since the top of the perforated roll is slightly lower than the high speed tapes, the next sheet introduced from the high speed, tapes will fiow over the trailing edge of the previous sheet now traveling at the reduced speed. This places the two sheets in an overlapping relationship. As the trailing edge of the second sheet leaves the high speed tapes, vacuum is again applied, the second sheet is slowed. The theoretical maximum physical limit to the amount of overlap that can be accomplished in this way is slightly less than the sheet length minus the width of the exposed portion of the perforated roll. This is far greater than previous methods could attain.

In FIG. 5, the apparatus 1 is employed to retard sheet speed to the point where a sheet can be discharged directly into a layboy box 3 with no damage to the sheet leading edges, as might occur if the sheets were discharged directly from the high speed conveyor 2. In this configuration, the inner control roll is rotated at the speed of the cutter flybar and the outer roll is rotated at a speed slow enough to prevent sheet leading edge damage as the sheets are discharged into the layboy box 4.

In FIG. 6, the apparatus is employed to direct sheets downward onto a conveyor 5 for discharge into another layboy box 6. This configuration could be employed to reject damaged sheets into a layboy box 6, permitting undamaged sheets to pass to conveyor 3. In this configuration, suitable means for sensing damaged sheets and for actuating apparatus 1, and also suitable means for permitting undamaged sheets to pass over apparatus 1 to conveyor 3 would be required. This configuration could also be employed to alternately fill layboy boxes 4 and 6, apparatus 1 being operated to direct sheets downward to layboy box 6 when layboy box 4 is being emptied or replaced with an empty layboy box. In the FIG. 6, configuration, the apparatus would be synchronized to apply suction to the leading edge of the sheets to be directed downward onto conveyor 5, with the inner roll rotated at the speed of conveyor 2 and the outer roll rotated at the speed of conveyor 5.

It is believed that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiments. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly our intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits. For example, the vacuum chamber arrangement of the FIGS. 1-3 embodiment could be applied to FIG. 7 embodiment and vice versa.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Sheet control apparatus which comprises means providing an outer moving surface exposed to sheet material with openings therethrough; an inner rotary valving mechanism having an opening therein rotatable into communication with the outer moving surface openings, and means drawing a continual negative pressure in said rotary valving mechanism such that suction is applied to the outer moving surface openings when the rotary valving mechanism opening is in communication with the outer moving surface opening; and means for rotating said rotary valving mechanism in timed relation to sheet material speed to subject sheet material to periodic suction so that such sheet material is drawn onto said moving surface.

2. Apparatus according to claim 1 wherein said means providing an outer moving surface comprises a rotatable perforated cylinder enclosing said rotary valving mech anism.

3. Apparatus according to claim 1 wherein said means providing an outer moving surface comprises a plurality of endless tapes spaced apart and enclosing said rotary valving mechanism.

4. Apparatus according to claim 1 including a low speed conveyor with its receiving end adjacent said means providing the outer moving surface; said outer moving surface travelling at the speed of said conveyor.

5. Apparatus according to claim 1 including a layboy adjacent to said means providing the outer moving surface for receiving sheet material from said outer moving surface at a reduced speed.

6. Sheet control apparatus which comprises a rotatable inner slotted control cylinder; a rotatable outer perforated cylinder concentrically enclosing the inner cylinder; a vacuum chamber partially enclosing the concentric cyllnders such that a portion of the periphery of the outer roll is exposed for contact with sheet. material passing thereacross; said outer cylinder being adapted to rotate at the speed selectable independently of the inner cyllnder speed; the inner cylinder slots being positioned such that periodic suction can be effected to draw a predetermined sheet material section onto the rotating exposed outer periphery.

7. Apparatus according to claim 1 whereln sa1d vacuum chamber is provided with longitudinal sealing strips that have arcuate faces in contact with the outer cylinder periphery; and wherein said inner cylinder is provlded with longitudinal seal strips contacting the mner surface of said outer cylinder such that rotation of sa1d mner cylinder so as to expose at least one of said slots to the vacuum chamber effects periodic suction as air is drawn therethrough.

8. Sheet control apparatus which comprises an mner rotatable slotted control cylinder; a tape conveyor having a plurality of tapes spaced apart and enclosing sa1d control cylinder; a suction chamber enclosing sa1d control cylinder with an opening to a movmg course of sa1d tape conveyor; the rotation of control cyllnder slot effecting a periodic suction to draw a predetermined sheet material section onto said outer moving surface 9. Apparatus according to claim 8 wherein the open ng in said suction chamber is provided with sealing str ps longitulinally partitioning such opening, said sealing strips sealably contacting the outer surface of sa1d control cylinder. 0

10. Sheet handling apparatus WhlCh comprises a hi h s eed conveyor; and

sheef cor itrol apparatus adjacent the discharge end of said high speed conveyor comprises a rotatable mner slotted control cylinder; a rotatable outer perforated cylinder concentrically enclosing the inner cyllnder; a vacuum chamber partially enclosing the concentrlc cylinders such that a portion of the: perlphery of the outer roll is exposed for contact with sheet material passing thereacross; said inner cylinder being adapted to rotate at the speed of sheet material approaching the apparatus; said outer cylinder bemg adapted to rotate at the speed selectable independently of the inner cylinder speed; the nner cylinder slots being positioned such that periodic suction can be effected to draw a predetermined sheet material section onto the rotating exposed outer periphery.

11. Apparatus according to claim 10 including a low speed conveyor with its receiving end adjacent said sheet control apparatus; the outer roll being rotated at the speed of said low speed conveyor.

12. Apparatus according to claim 10 including a layboy adjacent to said sheet control apparatus for receiving sheet material from said sheet control apparatus at a reduced speed.

13. Sheet control apparatus which comprises a rotatable slotted control cylinder; a rotatable perforated outer cylinder concentrically enclosing the inner cylinder and rotatable independently of said inner cylinder; a plurality of seal strips longitudinally extending along said inner roll in rotating sealing contact with the inner surface of said outer cylinder; a vacuum chamber comprising end walls peripherally enclosing the side and bottom portions of said outer cylinder, and forward and rearward walls extending between the end walls and defining an opening leading from said vacuum chamber; a plenum chamber communicating with said vacuum chamber through the vacuum chamber opening; sealing strips with arcuate faces contacting the outer surface of said outer cylinder mounted 15 on said vacuum chamber forward and rearward walls on opposite sides of said vacuum chamber opening so that suction is effected when one of the inner cylinder slots sweeps between the sealing strips.

References Cited UNITED STATES PATENTS 2,969,980 1/1961 claybourn 271-68 3,178,174 4/ 1965 Schneider 271'74 3,190,644 6/1965 Schwebel 271-46 3,218,897 11/1965 Geigenmiller 27146 3,3 36,028 8/ 1967 Schonmeier 27 l-46 RICHARD E. AEGERTER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,432,161 March 11, 1969 Ingvald Dale et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, line 28, the claim reference numeral "1" should read 6 Signed and sealed this 31st day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

